Histomonas meleagridis

Lesions on turkey liver due to histomoniasis and secondary bacterial infection. Characteristic lesions of the disease termed "Black head", multi-focal white pinpoint lesions, can be seen around multiple dark, slightly depressed areas, on a generally enlarged liver. Without secondary bacterial infection, Histomonas infections are only mildly pathogenic. In turkey flocks not on prophylactic antibiotics,histomoniasis mortality rates may reach 100%.

Leishmania infantum

​Amastigotes of Leishmania infantumwithin macrophages in a Romanowsky stained spleen impression smear from a dog. Note darkly staining kinetoplasts and nuclei within the ovoid amastigote bodies.

​

Cutaneous leishmaniasis lesion in a brown rat. ​

Trypanosoma cruzi

​Trypomastigotes of Trypanosoma cruzi in a Romanowsky stained blood smear. Note the darkly staining kinetoplasts and nuclei, as well as evident undulating membranes.

A collection of Trypanosoma cruziamastigotes seen within a cardiac muscle cell. Replication of T. cruzi takes place as intracellular binary fission of the amastigotes, within the cells of the reticuloendothelial system and striated muscle.

Trypanosoma equiperdum

​Trypomastigate of Trypanosoma equiperdum,causative agent of dourine in horses, in a Romanowsky stained blood film. This trypanosome is unique in that it is sexually transmitted, and is not known to require an arthropod host for development.

Trypanosoma lewisi

​Trypanosoma lewisitrypamastigote in a blood smear from a rat. Transmitted by the rat flea Ceratophyllus fasciatus, T. lewisi is generally non-pathogenic.

Trypanosoma theileria

​Trypanosoma theileri trypomastigote, a hemoflagellate of cattle, transmitted and hosted by Tabanid flies. Trypanosoma theileri trypamastigotes are among the largest, ranging from 60 - 120 μm in length, with a well developed undulating membrane and a well defined free flagellum.

Tritrichomonas foetus

Trichomonas gallinae

​Lesions of trichomonaisis, commonly referred to as 'canker' or 'frounce', consisting of diffuse multifocal areas of caseous necrosis in the esophagus and oropharynx of a columbiformes. Lesions are found in the mouth, pharynx, esophagus, and crop, rarely posterior to the proventriculus.